The present invention relates to an assembly of complex mechanical seals for a vertical multiple stage pump. More particularly, the invention relates to a cassette type assembly of complex mechanical seals comprised of a balance plate and a mechanical seal. Specifically, the invention relates to replacing the balance plate and mechanical seal more easily so as to guarantee the efficacy of the pump.
There are several ways to overcome the problem of force being applied horizontally against a vertical multiple stage pump. For instance, one could use bearing directly against the horizontally pushing force, or use a balance holes, or use balancing dice. However, in general, a balance plate is usually adapted to solve the horizontal force problem.
When the balance plate is used as a balance apparatus for a vertical multiple stage pump, the main structure of mechanical seal is arranged on the upper part of the pump.
Thus the position of the mechanical seal provides for a leaking out gate in order to prevent the gas from being trapped on the upper part of the pump. This allows the mechanical seal to stay cool and stay lubricated by the use of movable liquid, so as to seal the pump and the stabilizing work.
In addition, in the conventional balance apparatus, the gas between the balance plate and fixed element will increase the amount of gas leakage due to the decrease of gas pressure thus lowering the efficacy of the pump.
Further, the size of the balance plate is to close too the inlet size of the blade wheel and it is an independent apparatus.
Thus, the vertical and the horizontal size require a certain space to satisfy the requirement of the operation as mentioned.
Therefore, the maintenance work of assembling and disassembling of such an apparatus is very difficult because it takes a long time to disassemble and assemble the mechanical seal and balance plate.
The inventor discovered the balance apparatus of the conventional pump is accompanied with the above mentioned defects. To overcome such defects, a cassette complex structure for a novel mechanical seal and balance plate is provided.
In addition to quickly executing the assembling and disassembling of the apparatus, the present invention maintains the efficacy of the pump so as not to be influenced by the changing of pressure, which is the main object of the present invention.
According to the present invention, the mechanical seal and balance plate are combined together. Thus the whole structure is more closely and firmly packed and provides a space saving, which is the further object of the present invention.
The present invention provides a complex mechanical seal for a vertical multiple stage pump, which comprises: a hollow cylinder fixed plate positioned in the final stage of outlet gate in the vertical multiple stage pump. It is coupled with an inner wall surface of fixed barrel is to form a sealed face. The bottom hole of the fixed barrel is used as the passage for the pump axle. A long axle bushing in the inner pant of the fixed plate is fixed on the pump axle.
A balance plate is positioned below a long axle bushing and combined with the long axle bushing to become part of it. The circumference of the balance plate has a promotion flange to divide the inner wall surface and to form a gap. The mechanical seal is fixed on the upper region of the balance plate and fixed on the long axle bushing.
A return water passageway is connected to the upper part of the balance plate and is also connected to the inlet of the pump, within the fixed plate, and the high pressure region
A high pressure region A and a low pressure region B are formed at the lower part and the upper part respectively. These differential pressure forces are need as the pushing force of the balance axle.
Simultaneously, the complex structure of the balance plate and mechanical seal is accomplished more easily and quickly in assembly and disassembly.
According to the present invention, the mechanical seal and balance plate are combined together, and the circumference of balance plate is to form various annular grooves.
Said combined structure is able to keep a small distance with the inner face of the circumference of the fixed barrel.
Thus the combination of balance plate and axle is to keep a same gap distance from the inner face doing rotation and change of pressure.
The amount of leaking out is not influenced to keep unchanged so as to maintain the efficacy of the pump,
In addition, according to the present invention, the combined mechanical seal and balance plate are disassembled and assembled together from a pump axle. Therefore, the work of disassembling and assembling are easier and maintenance is easier as well.
According to the present invention, the complex structure of mechanical seal and balance plate is to form an outlet pipe line connected to the inlet. Thus when the pump starts to operate, it is able to provide air to the outlet automatically. This is another object of the present invention.
The present invention will be apparent in its novelty and features after reading the detailed description of the preferred embodiment thereof in reference to the accompanying drawings.